Nearly every doctor, researcher, and health expert agrees that just about everyone should take fish oil.
It’s well-established that it can support heart, blood vessel, brain, immune, and joint health, as well as mood and memory.
Emerging research shows that fish oil may also support strength, muscle gain, and workout recovery.
One of the best examples of this comes from a 2023 study conducted by researchers at Baylor University on 28 men and women with at least six months of weightlifting experience.
One group took 4.5 g of fish oil daily (~2.3 g of EPA and ~1.6 g of DHA), and the other took a placebo for 10 weeks. During the study, participants trained 3 times weekly on nonconsecutive days, doing 3–4 sets of the squat, leg press, leg extension or leg curl, bench press, shoulder press, seated cable row, and lat pulldown in each workout.
The results showed that the fish oil group experienced a 73% greater increase in their bench press one-rep max relative to the placebo group (~24 lb. vs. ~14 lb.).
The weightlifters who took fish oil also increased their squat one-rep max (~53 lb. vs. ~41 lb.) more than the weightlifters who took a placebo, and they tended to lose slightly more fat and gain a bit more lean body mass (a proxy for muscle), though these differences weren’t statistically significant.
While the results were modest, it’s a green flag in favor of fish oil: It certainly boosts health, likely improves performance, and may help you build muscle and lose fat faster.
Other research shows that fish oil appears to boost muscle protein synthesis (MPS), the creation of new muscle proteins.
For example, in a study conducted by researchers at Washington University, nine adults took fish oil for eight weeks. Researchers tested their response to an infusion of insulin and amino acids, the building blocks of protein (and thus muscle).
During this test, muscle protein synthesis was 34% higher after supplementing with fish oil. The researchers also found an increase in the activation of mTOR, the key protein responsible for telling your muscle cells to grow bigger and stronger.
Finally, emerging evidence shows that fish oil may also boost workout recovery and muscular efficiency.
A 2018 study conducted by researchers at the Universities of Otago and Stirling had 20 professional rugby players consume a protein supplement with or without 2.2 grams of EPA+DHA daily during five weeks of training. The fish oil group reported less soreness, and countermovement jump performance (a test of explosive leg power) increased by 4.6% but dropped by 3.4% in the players who took a placebo.
Studies from the University of Birmingham and the University of Wollongong have both found that fish oil supplementation helped trained cyclists to maintain a lower heart rate, oxygen consumption, and perceived exertion during a cycling test, indicating greater muscular efficiency during exercise. That said, fish oil didn’t improve actual cycling performance in either study.
How does fish oil do all of this?
The two primary fatty acids in fish oil—eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)—become part of your cell membranes, which positively impacts most aspects of cellular function.
Basically, fish oil seems to “grease the gears” of the systems your body uses to build and repair proteins, generate energy, transmit nerve signals, regulate inflammation and oxidative stress, and supply oxygen and nutrients to cells, all of which are critical to myriad different functions related to muscle gain, recovery, and athletic performance.
Now, there are a few caveats to all of this.
First, several recent studies have failed to see any meaningful increase in muscle protein synthesis or actual muscle and strength gain after taking fish oil supplements.
Second, even the most positive studies have only found relatively small benefits. Don’t believe anyone who tries to pass off fish oil as some sort of natural, legal steroid: It won’t help you gain 20 pounds of muscle or add 50 pounds to your bench press in three months.
Third, it’s important to remember that most of the proposed benefits of fish oil come from avoiding deficiency of EPA and DHA, rather than artificially elevating your body’s natural levels of these fatty acids. If you’re getting enough from your diet, then you probably won’t benefit from taking more.
Some research has even found that taking excessive amounts of fish oil is linked to a greater risk of atrial fibrillation (an irregular heartbeat) and oxidative stress.
That said, while it’s possible to get sufficient EPA and DHA from whole foods, this isn’t always practical.
You’d need to eat about one four-ounce serving of fatty fish per day to get 1.8 grams of combined EPA and DHA per day, assuming about 2 grams per serving. And most people simply don’t eat that much fatty fish.
What’s more, many foods that are often said to be “good” sources of EPA and DHA, like eggs, cheese, and milk, have such vanishingly small amounts that they’re hardly worth counting. For example, even omega-3-enriched eggs often contain about 65 mg of combined EPA and DHA per egg. You’d have to eat about 30 eggs per day just to reach 1.8 grams of combined EPA and DHA.
Even if you did eat one large portion of fatty fish per day, it’s no guarantee you’d get enough EPA and DHA. The species of fish, where it was harvested, the season it was harvested, how it was processed, and what its diet consisted of can all impact EPA and DHA levels and the ratio of these two fatty acids.
What’s more, some fish, like swordfish, bigeye tuna, and king mackerel, can be high in mercury, making it potentially dangerous to get all of your EPA and DHA from these fish alone. (And in case you’re curious, fish with the lowest mercury levels include salmon, sardines, and anchovies.)
Thus, although I’m generally an advocate for getting as many nutrients from whole foods as possible, getting your EPA and DHA from fish oil supplements is often the healthier, more practical choice.
If you’re looking for a high-potency and high-absorption fish oil that provides a clinically effective dose of lab-tested omega-3 fatty acids, try Triton. It provides 2,400 milligrams of EPA and DHA per serving from VivoMega™ fish oil, a 100% reesterified triglyceride fish oil that delivers EPA and DHA in their natural triglyceride form, which is better absorbed than the cheaper ethyl ester form commonly used in lower-quality fish oils.